Plastic reinforced bowling pin and method of making same



April 26, 1966 w. E. PONEMON 3,248,114

PLASTIC REINFORCED BOWLING PIN AND METHOD OF MAKING SAME Filed Aug. 15, 1962 vAcuuu IMPREGNATE I B I I I cum:

' GRIND 7 (OPTIONAL) nzsm FIG 3 I l I SHAPE 7 now a cum-z oocron BLADE (CAVITY now) v INVENTOR WARREN E. PONEIION cunt BY ATTORNEY United States Patent 3,248,114 PLASTIC REINFORCED BOWLING PIN AND METHOD OF MAKING SAME Warren E. Ponemon, Syosset, N.Y. '(16 Huckleberry Lane, Oyster Bay, N.Y.)

Filed Aug. 15, 1962,-Ser. No. 217,097 4 Claims. (Cl. 273-82) This invention relates to an improved bowling pin and method of making same.

The term bowling pin, as employed herein, is intended to encompass duck pins, ten pins, candle pins, and other like devices.

Bowling pins in current use are made of laminated hard wood stock which is turned in a lathe to shape and then coated with a layer of synthetic resin. Such pins, when used in a busy alley, last about three months, after which time they must be replaced. Since a typical automatic pin-setting alley employs twenty pins, it will be appreciated that the life of a pin is of great economic importance to the operation'of the alley. There is need for a reinforced bowling pin; however, the reinforcing process employed must be economically feasible, and must not interfere with the normal playing qualities of the pin.

One of the unusual problems in making a satisfactory bowling pin is that the pin must produce a satisfactory sound when struck by the bowling ball. Players are quick to note the difference in tone between a new pin and an old battered pin. Therefore in addition to having a satisfactory tone, it is desirable that the tone sound consistently. like that provided by a new pin of the conventional type. Pins, in general, must conform to the measurement specifications established by bowling associations in order to be accepted for tournament play. The prior art wood pin suffers from a tendency to change its -bounce effect with use. As the pin is repeatedly hit by the bowling ball, it becomes denser and as a result, an old pin, does not react with the same sound as a new pin. On the other hand, the improved pin of this invention provides uniform bounce response over its useful life. As explained more fully hereinafter, the pin of this invention provides a high pitched vibration when struck, having a sound effect like that produced by a new pin. The process of this invention fulfills these requirements. i

Briefly stated, the invention comprises the provision of a resin bonded, braided layer of filaments having high tensile strength, such as glass fiber, steel wire, nylon, Orlon, and other like materials. The braiding is applied under high tension.

The process of this invention. is to' be sharply distinguished over prior methods wherein a knit stocking is stretched over a mandrel and impregnated with a cellulose composition. In'this prior method the filaments are not uniformly stretched as reliance is placed on the yielding of the knit structure.

Accordingly, it is an object of this invention to provide an improved reinforced bowling pin, characterized by a long life.

It is a further object of this invention to provide a bowling pin having a braided reinforcing layer.

It is a diiferent object of this invention to provide a bowling pin yielding a high pitched tone when struck.

Still another object of this invention is to provide a bowling pin reinforced by a glass fiber braiding bonded with an epoxy resin.

Yet another object of this invention is to provide a "ice Patented Apr. 26, 1966 satisfactory bowling pin which may be made of softer or cheaper wood.

Yet a further object of this invention is to provide a satisfactory bowling pin which may be made of less wood.

Another object of this invention is to provide-a method of reworking the conventional wooden pins.

These and still further objects and advantages will, in part, become obvious and will, in part, be pointed out with particularity as the following description proceeds taken in conjunction with the accompanying drawing.

In the drawing: FIG. 1 is a front elevation of the pin of the present invention, partly broken away, with stages in the manufacture of the pin illustrated diagrammatically.

FIG; 1A is a pictorial View of a conventional laminated pin construction, showing schematically the effect of impact by a bowling ball.

FIG. 2 is a perspective view of a braiding machine used with a pin of the present invention.

FIG. 3 is a flow chart showing the process of the present invention.

In the various figures of the drawing, like reference characters designate like parts.

Referring now to the drawing, the bowling pin of the present invention, characterized generally by the numeral 10, comprises the standard pin portion 12, neck 14, and body portion 16, of arcuate configuration, and formed of a wood shaped by woodworking means well known in the art. Standard bowling pins, as hitherto manufactured, have generally been of laminated hard maple. Such a structure, for example, is illustrated in FIG.- 1A, wherein a laminated structure type of bowling pin 2 is shown at the moment of impact by a bowling ball 4. The stress on the laminations 6, here illustrated in exaggerated form, in phantom, causes relatively rapid wear of the pin by loosening the laminations 6 and causing them to separate slightly from the pin body 8.

The bowling pin of the present invention comprises a resin bonded woven covering 28, over a wooden mandrel 18. The mandrel which defines the shape of the finished.

pin need not be made of prime hard maple and can be made of low cost, softer woods.

bonded covering will preventthe undesirable effect of impact from occurringas in connection with the just described prior device. It will be appreciated that the resulting substantial saving in cost will provide important advantages over the prior art. I In view of the reinforcing process, the mandrel I8 is shaped approximately oneeighth of an inch less in diameter as to head, neck, and body portions 12-16. Mandrel 18 is then placed in position on a braiding machine 20, FIG. 2, of conventional construction, and provided with a plurality of rotatable and displaceable spools 22. Mandrel 18 is rotated and strands 24- from the individual spools are formed over the pin in a braided configuration, illustrated diagrammatically in FIG. 1. A preferred material for the strands in Fiberglas filaments having a diameter of 0.00038", 7

wound with 204 filaments to the end. Maximum tension .is maintained on the strand during this operation, the

amount of tension being limited only by the breaking point of the strand and the crushing point of the wood. While hard maple can be subjected to the maximum tension, good results will be obtainable even with the softer and cheaper grades of good. Tension in the range of 0.1 to 1.0 lb. per glass fiber strand has been found suitable.

The mandrel may be formed from laminations but the tough woven resin After braid coating 26 is formed over mandrel 18, the pin is vacuum-impregnated in a bath of resin. It is to be noted that the braiding process is done dry. After the resin bath, the article is placed in an oven and cured, whereby resin coating 28 is formed over the surface of the pin. A preferred resin for this purpose is a plasticized epoxy resin. A typical formula for this resin is as follows:

Parts by weight Plasticizer A is a glycidyl ester of mixed dimers and trimers of long chain unsaturated fatty acids having an epoxide value of 0.242 equiv./100 grams of resin and a hydroxyl value of 0.019 equiv./100 grams of resin. The method of making this plasticizer is disclosed in US. Patent 2,940,986.

Epoxy resins are condensation products of epichlorhydrin and bisphenol A. The particular resin used in the example was a low. viscosity liquid glycidyl ether bisphenol-epichlorhydrin, with an epoxide equivalent of from about 0.5 gram/100 grams of resin. Other epoxy resins may be employed, their selection being a matter of choice from lists of commercially available products having suitable properties. The epoxy resin may be plasticized with other materials, for example, Thiokol Chemical Corp. LP-3 which is mercaptan terminated,

long chain aliphatic polymer containing disulphide linkages having an average molecular weight of 1000. Suit able formulations are fully described in the Thiokol Chemical Corp. brochure Liquid Polymer/ Epoxy Resins Systems (May 1960). Still other plasticizers are commercially available. V

A number of resinous compositions have been used with success in fabricating the novel reinforced plastic pin of this invention. Although epoxy resins are generally preferred because of excellent adhesion to glass, excel-. lent mechanical and age-resistant properties, and freedom from shrinkage and evolution of volatiles upon curing, phenolic, polyester, melamine, novolacs, or other suitable resins may be employed in order to reduce the cost of the article. a

After the resin impregnation, a smooth surface is formed on the article by one of the various processes well known in the art. Preferably, a doctor blade having the desired contour is positioned against the pin which is rotated so as to uniformly distribute the excess resin over the surface of the pin. The resulting shaped pin is then cured. An alternative procedure may be followed in which the curing is carried out in a conventional matched cavity mold so that the surface resin layer of the final product is of the desired configuration. It is to be noted that the pin may be colored by employing suitable pigments in the resin. Still another procedure is shown in FIG. 3 wherein the covered resin impregnated pin is cured in an oven at a temperature suitable for the resin. The surface is then ground to remove excess resin runs and other irregularities. Care should be exercised to avoid grinding away portions of the filaments which would, of course, weaken the structure. ground surface of the pin may be resin coated. usually necessaryto grind the pin bottom to provide a true base 33. After the braiding operation, there may remain a top knot which can be cut off. After the resin is cured, final trimming of the top can readily be effected by grinding. These steps are indicated schematically in the process diagram of FIG. 3.,

Optionally, the

There has thus been provided in the present invention a resin-bonded braided structure wherein the strands provide high impact resistance due to the high tensile strength and high modulus of elasticity of the strand material employed. The high degree of elasticity and strength of the finished pin permits the pin to be made with a central bore 29, as shown in FIG. 1. Before braiding, the base portion of the pin may beprovided,

with a nylon base ring 30, which ring is conventional in the art. annular shoulder. 32 of the base of the pin and the ring 30 added in a final assembly operation.

There has been disclosed heretofore the best embodi-' ment of the invention presently contemplated and it is to be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is: 1. The method of reinforcing a Wooden bowling pin comprising braiding a tight fitting .cover, in situ, over a wooden core having a standard bowling pin shape, said cover comprising strands composed of a plurality of filaments and impregnating said resulting cover with a synthetic resin layer.

2. The process of claim 1 including the steps of curing said resin and grinding said resin-strand layer .to a final contour.

3. The process of claim 1 including the step of completely coating said pin with synthetic resin and molding said pinyin a female mold.

4. The process of claim 1 including the step of rotating the pin againsta doctor blade having the desired contour after the cover is impregnated with the resin layer whereby a smooth outer surface is formed.

References Cited by the Examiner UNITED STATES PATENTS RICHARD C. PINKHAM, Primary Examiner.

DELBERT B, LOWE, Examiner.

Optionally, the braiding maybe formed in Sawyer 87-6 

1. THE METHOD OF REINFORCING A WOODEN BOWLING PIN COMPRISING BRAIDING A TIGHT FITTING COVER, IN SITU, OVER A WOODEN CORE HAVING A STANDARD BOWLING PIN SHAPE, SAID COVER COMPRISING STRANDS COMPOSED OF A PLURALITY OF 